Thermoplastic polyurethane materials have many uses as fabricated articles because of their physical properties and their ease of processing. However, as thermoplastic materials, their use at high temperatures is often precluded or limited, they have a tendency to permanent set, and may be adversely affected by certain solvents. Stable polyurethane elastomeric compositions that can be vulcanized by free radical curing agents included during or after processing would be of value in that the disadvantages mentioned above would be at least partially offset.